In recent years, an environment for viewing and recording a three-dimensional video using a consumer device is being developed. Especially, Blu-ray Disc Association (BDA) has determined a standard for a three-dimensional image format. A market of devices (such as TVs and mobile phones) that support three-dimensional video has started to grow. It is expected that digital broadcasting of three-dimensional (3D) video will be widely available in the near future.
In the broadcasting of three-dimensional video or transmission of three-dimensional video, a broadcast wave may not be appropriately received due to low signal strength in a transmission network. When a transmission error (such as an error indicating that a broadcast wave cannot be appropriately received) occurs, video data or audio data cannot be accurately decoded. In order to encode an image, a temporal-directional prediction is performed. Thus, when a picture in which an error occurs is a picture (such as an I picture or a P picture) that is referenced for prediction of another picture, information of the error is referenced, and the error is transferred to multiple frames. When the error is transferred to the multiple frames, a range that is affected by the error is increased.
To avoid the transfer of the error, there is a technique for concealing the error (occurring in the error picture or an error region of the picture) using an accurately decoded picture or a predetermined region of the accurately decoded picture.
For example, Japanese Laid-open Patent Publication No. 2006-203598 discloses a technique for performing a panning detection and for, when an error occurs, setting a motion vector for a motion compensation and for a block (error block) in which the error occurs on the basis of a motion vector of a macro-block (MB) located near the error block.
In addition, Japanese Laid-open Patent Publication No. 2007-325206 discloses a technique for determining the validity of a macro-block located near a macro-block to be restored, acquiring context information for image restoration from the macro-block determined to be valid, and calculating an estimated motion vector to be used for the restoration.